If Playstations and XBoxes haven't yet killed off the time-honored, time-consuming hobby of gluing model airplanes, maybe the nation's defense contractors will do the job.

Model manufacturers say companies like Boeing, Lockheed Martin and United Technology's Sikorsky have in recent years bombed them with letters and phone calls demanding they cough up royalty fees on kits of military aircraft. They include some hobbyist favorites, like the B-17 bomber and P-51 (both Boeing), the F-16 fighter jet (Lockheed Martin) and the Black Hawk helicopter (Sikorsky).

Modelmakers have long paid royalties to automakers and more recently to railroad companies for the rights to make cars and trains. Boeing collects a royalty for models of commercial planes, like the 747. But military aircraft are different, the modelmakers say. They were commissioned by the U.S. government, and therefore their trademarks should be in the public domain. "Since taxpayers paid for them, how does a company lay claim to it?" says Edward Sexton, vice president of product development at Revell-Monogram. A quarter of his company's 300 different models are military aircraft.

Model kits cost anywhere from $8 to $50 wholesale (half the retail price), ranging from small, simple models to 2-foot-long versions that seem to replicate many of the fine details of the original. A 6% royalty, say, would add 48 cents to $3 per kit, not counting administrative costs. A few manufacturers in the $100 million U.S. market are paying, but many, like
Revell-Monogram, have resisted.

Lockheed Martin just wants to ensure that replications of its planes are "high quality, safe and accurate," says spokesman Thomas Greer. It's a stretch to think the Air Force would stop ordering a jet if they saw a crappy plastic version at Toys "R" Us. But Greer says federal law lets suppliers retain rights over the aircraft's name when it comes to outsiders profiting from the trademark. The royalty money just covers administrative costs, he says. "Our goal is not to make life more difficult for the hobbyist."